Month: February 2010

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Porcupines

Porcupine Quill
Copyright © 2009 Jim Cane

We address a prickly topic this week: one of the more intriguing and unusual mammals native to Utah – the porcupine. These shambling, large rodents would be defenseless if not for their dense cover of modified hairs called quills. Porcupines have about thirty thousand quills covering their back and tail. When disturbed, they clack their teeth in warning and raise the long quills on the back to form a random pattern that completely protects them. The quills are not hollow as some people believe. Porcupines do not throw their quills; an attacker must make contact. But once they do, the backward facing microscopic barbs on the greasy quill tips draw the quills into the attacker’s flesh. The short quills on the tail are particularly treacherous. In a split second tail flip, quills can penetrate the body so deeply that they disappear.

Porcupines range throughout Utah in diverse habitats. They are predominately nocturnal. Their diet is vegetarian. In spring they feast on leaf buds of deciduous and conifer trees and succulent ground vegetation. In summer and fall, they nip off the ends of branches to get to the leaves, nuts and fruit. Nipped branches frequently litter the ground under trees where porcupines dine. In winter, they resort to twigs and needles of evergreens and the inner bark of trees. This winter diet is nutrient poor and starvation takes its toll.

Porcupine in Tree
US FWS Digital Library

Porcupines are perhaps easiest to spot in winter when they may be seen high up in small conifer trees. Their tracks in the snow are distinctive. The foot prints are large and shows the whole foot. The belly usually scuffs in the snow and sometimes you can even detect the side-to-side sweep of the tail. So in these waning days of winter, remember to be watchful for Utah’s prickliest mammalian resident.

This is Linda Kervin for Bridgerland Audubon Society.

Credits:

Pictures:

Text: Linda Kervin, Bridgerland Audubon Society

Additional Reading:

https://wildlife.utah.gov/projectwild/newsletters/01fallwinter-gw.pdf

www.hsus.org/wildlife/a_closer_look_at_wildlife/porcupines.html

https://science-ed.pnl.gov/pals/resource/cards/porcupines.stm

Roze, Uldis, 1989. The North American Porcupine. Washington, D.C.: Smithsonian Institution Press. Also available as https://www.amazon.com/North-American-Porcupine-Uldis-Roze/dp/0801446465

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Snowshoe Hare

Snowshoe Hare Summer Coat
Courtesy US National Parks Service

Hi, I’m Holly Strand from Stokes Nature Center in beautiful Logan Canyon.

The approach (opening) of the 2010 Olympics in Vancouver brings back fond memories of Utah’s stint as host of the winter games back in 2002. Many Utahns will recall that among Salt Lake’s three Olympics mascots was “Powder,” a playful snowshoe hare.

Powder represented “faster” in Salt Lake’s triumvirate motto of “Citius, Altius, Fortius” (Faster, Higher Stronger) and the description is apt for the nimble mammal that owes much of its survival to its comically large feet.

USU wildlife biologist Dustin Ranglack says the snowshoe hare’s feet are ideally suited for racing from predators in deep mountain snow. “Snowshoe hares are known as the ‘Snickers bars of the forest’ because they’re a popular treat for a host of carnivores, including coyotes, foxes, lynx, bobcats, bears and birds of prey.”

Ranglack notes that the hare, which he describes as “the cutest bunny rabbit you’ve ever seen,” sports another defensive trait that serves the animal well: its distinctive camouflage coat. In winter, the hare’s soft, fine fur turns white to blend into the snowy terrain. As spring thaws the wintry landscape, the hare’s fur turns brown to help it elude predators.

Snowshoe Hare Winter Coat
Courtesy USDA Forest Service

Coupled with its prolific breeding habits, the snowshoe appears to have a robust arsenal of defenses as it feeds at night following well-worn forest paths to feast on trees, shrubs, grasses and plants. Yet scientists observe that climate change may disrupt photo cycles that keep the color of hares’ fur in sync with its surrounding landscape. A white hare may end up sitting on brown earth in full view of ravenous predators, upsetting the delicate balance of advantage.

“The hares are fast, yes, but their best mechanism of defense is camouflage,” Ranglack says.

Thanks to Mary-Ann Muffoletto and Utah State University College of Natural Resources for supporting the development of this Wild About Utah program.

For Wild About Utah and Stokes Nature Center, I’m Holly Strand.
Credits:

Images: Courtesy US Forest Service and US National Parks Service

Text:     Mary-Ann Muffoletto, Holly Strand, Stokes Nature Center

Sources & Additional Reading

Dustin Ranglack, USU Department of Wildland Resources https://www.usu.edu/ust/index.cfm?article=35951

Huang, Lilly. “The Case of the Disappearing Rabbit,” Newsweek, July 25, 2009.https://www.newsweek.com/id/208445

Snowshoe Hare Lepus Americanus, National Geographic, https://animals.nationalgeographic.com/animals/mammals/snowshoe-hare.html

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Calls of Two Common Owls

Calls of Two Common Owls: Great Horned Owl Photographer: Karen Laubenstein US FWS Digital Library
Great Horned Owl
Photographer: Karen Laubenstein
US FWS Digital Library

Societies and peoples the world over have harbored superstitious fears of owls. In truth, only small mammals and other like-sized prey should tremble in the presence of these fierce, stealthy predators. Most owls hunt by night, aided by light-sensitive vision and keen directional hearing. Most owls also call at night, and although not melodic, you can learn to identify owls by their calls. Today I will feature two common owls of the nine species that you can expect in Utah.

The Great Horned Owl is Utah’s largest owl, the size of a Red-tailed hawk. It’s correspondingly loud and booming call is a series of “who’s”.

[Kevin Colver: Great Horned Owl (Private Library)]

Great Horned Owls breed early, so expect to hear their hooting duets on our long winter nights. They hunt at night from a tree perch, swooping down to catch their prey. They primarily feed on rodents, skunks and other mammals.

Western Screech Owl courtesy and copyright 2007 Lu Giddings
Western Screech Owl
Copyright © 2007 Lu Giddings

My second choice is the Western Screech Owl, one of our several small owls. Its look-alike eastern relative makes a whinnying cry, far different from the Western Screech Owl’s own call, which sounds like a bouncing ball.

[Kevin Colver: Western Screech Owl (Private Library)]

These smaller owls all feed on mice, voles and large insects. The male calls at dusk.

With persistence and luck, you can see these camouflaged owls roosting in the daytime too. Check out flocks of mobbing birds. Crows commonly raise a ruckus around Great Horned Owls, whereas chickadees will fuss stridently around small owls like the Western Screech Owl. But listening at night remains the best way to meet most of Utah’s owls.

Thank-you to Kevin Colver for the use of his bird recordings.

This is Linda Kervin for Bridgerland Audubon Society.

Credits:

Bird Recordings: Courtesy & Copyright Kevin Colver, Western Screech Owl & Great Horned Owl (Private Collection), https://wildaboututah.org/about-us/#7loons
Pictures: Great Horned Owl, Karen Laubenstein, US FWS Digital Library
Western Screech Owl, Courtesy & Copyright 2007 Lu Giddings
Text: Jim Cane, Bridgerland Audubon Society
Voice: Linda Kervin

Additional Reading:

Great Horned Owl, Utah Division of Wildlife Resources, Department of Natural Resources, State of Utah, https://fieldguide.wildlife.utah.gov/?species=bubo%20virginianus

Western Screech Owl, Utah Division of Wildlife Resources, Department of Natural Resources, State of Utah, https://fieldguide.wildlife.utah.gov/?species=megascops%20kennicottii

Backhouse, Frances, Owls of North America, Firefly Books, 2008, https://www.amazon.com/Owls-North-America-Frances-Backhouse/dp/1554073421

For Children:

Yolen, Jane, Owl Moon, https://www.amazon.com/Owl-Moon-Jane-Yolen/dp/0399214577

 

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Gila Monsters

‘Flower’ Gila Monster
Click for larger view
Copyright Daniel D. Beck
Central Washington University

Hi, I’m Holly Strand from Stokes Nature Center in beautiful Logan Canyon.

Turn up your radio and see if you can imagine the Utah creature who makes this sound.

[Sound: Jeff Rice, Gila Monster recorded at Arizona-Sonora Desert Museum]

That was the gasping breathing of a gila monster. It was recorded by Jeff Rice of the University of Utah’s Western Soundscape Archive.

Gila Monsters occur in pockets across the desert southwest. In Utah they are found only in Mojave habitat in the southwest corner of Washington County.

Once you get to know them, gilas are not at all monstrous. They are the largest of all lizards native to the U.S. An average gila might be 14-16 in. in length and would weigh about a pound and a half. They have thick sausage-like tails and large heads. The scales on the backs of these lizards resemble a beadwork pattern of black, orange, pink, and yellow.

Of the nearly4000 lizard species in the entire world only two are venomous. And one of them is the gila monster. But only a small amount of venom is introduced during a bite—not enough to kill a healthy human. Nevertheless, the bites are notoriously painful.

Gila Monster
Click map for larger view
Copyright Daniel D. Beck
Central Washington University

But gilas are reluctant to strike. Victims of bites have usually provoked the lizard in some way. Before biting, the lizard will hiss, and then back away from its would-be attacker. But if these warning efforts fail, it will latch on with frightening speed and tenacity. For gilas are the pitbulls of the lizard world.

A long-held belief has been that the breath of a gila monster is nauseating and toxic. In fact, it was even thought that gilas killed their prey with halitosis. The truth is that like many other animals, a frightened gila may regurgitate a recent meal when molested. Because gilas have such a slow metabolism, that last meal might be pretty old and smelly. Also, excited or reproductively active monsters can transmit a detectable body odor which some people find offensive.

These days, you’d be very lucky to see a gila monster in the wild. For in many areas their numbers are decreasing though collection and habitat loss. Another reason is that gila monsters are homebodies. They spend up to 97% of their lifetime tucked away in burrows or rock crevices.

For sources and pictures of gila monsters, see www.wildaboututah.org.

Thanks to the Rocky Mountain Power Foundation for support of this Wild About Utah topic.

For Wild About Utah and Stokes Nature Center, I’m Holly Strand.
Credits:

Images: Courtesy & Copyright Daniel D. Beck, Central Washington University

Text:     Holly Strand, Stokes Nature Center

Sources & Additional Reading

Beck, Daniel D. 2005. Biology of Gila monsters and beaded lizards

Beck, Daniel D.,1990. Ecology and behavior of the Gila Monster in southwestern Utah. Journal of Herpetology 24, pp. 54–68.

Brown, David. E. Carmony, Neil. B. 1999. Gila Monster : Facts and Folklore of America’s Aztec Lizard. Salt Lake City: University of Utah Press. https://www.amazon.com/Gila-Monster-Folklore-Americas-Lizard/dp/0874806003

Rice. Jeff. Western Soundscape Archive. J. Willard Marriott Library at the University of Utah, https://westernsoundscape.org/

State of Utah Natural Resources. Division of Wildlife Resources Species Database. Gila Monster. https://dwrcdc.nr.utah.gov/rsgis2/Search/Map.asp?Id=691 [Accessed Feb 2, 2010]

For More Information:

National Geographic . Wild Detectives: Gila Monster https://www.youtube.com/watch?v=59LRezTYkeo [Accessed Feb 2, 2010]

Arizona-Sonora Desert Museum https://www.desertmuseum.org/books/nhsd_gila.php [Accessed Feb 2, 2010]